LIES, LIES, ALL LIES!
This was said to me recently and I chewed the head off the person. You're never too old to start an exercise routine. You're never too old to learn something new. You're never too old to STOP BAD HABITS!
Now...you need to be extra careful so you don't hurt yourself but every gym I've ever been to has a trainer available to help and answer your questions. Also...the internet is chock full of information. Just find a trusted website and get your read on, open the front door and GET TO IT!